Feed mechanism for sewing-machines.



R. K. HOHMANN.

FEED MECHANISM FOR SEWING MACHINES.

APPLICATION FILED MAY 5, 1913.

1,1 10,629, Patented Sept. 15,1914.

3 SHEETS-SHEET 1.

THE AORRIS PETERS C0,, FHOTOYLITHDU WASHINGRIN, D. C.

R. K. HOHMANN. FEED MBGHANISM FOR SEWING MACHINES. APPLICATION FILED MAY5,1913.

Patented Sept. 15, 1914.

3 SHBETS-SHEET 2.

THE NORRIS PETERS (70.. PHOTO-LITHO" WASHINGTON, D. C.

R. K. HOHMANN.

FEED MECHANISM FOR SEWING MAGHINBS.

APPLICATION FILED MAY 5,1913.

1,1 10,629. I Patented Sept.15,1914.

THE NORRIS PETERS CO. PHOTIWLITHO, WASHINGLUN. 04 C.

RICHARD K. I-IOI-IMANN, OF

BELVIDERE, ILLINOIS, ASSIGNOR TO NATIONAL'SEWING MACHINE COMPANY, OF BELVIDERE, ILLINOIS, A CORPOBA'IION OF ILLINOIS.

FEED MECHANISM non SEWING-MACHINES.

Specification. of Letters Patent.

Patented. Sept. 15, 1914..

Application filed May 5, 1913. Serial No. 765,418. I

T0 all'whom it may concern Be it known that LARIOHARD K. Horr- MANN, a citizen of the United States, residing at Belvidere, county of Boone, State of Illinois, have invented certain new and useful Improvements in Feed Mechanism for Sewing-Machines, of which the following is a specification. I

This invention relates to cloth feeding mechanism for sewing machines and is shown applied to a machine ofthe rotary hook type.

It includes a novel arrangement for raising and lowering the feed member and for moving it horizontally and also novel means for changing the amount of longitudinal movement to vary thefeed.

The novel features of the invention will be apparent from the following description taken in connection with drawings.

In the drawings: Figure 1 is an end view of a machine showing the feed member and the operating shafts. Fig. 2 is a detail view of the mechanism for changing the length of the stitch. Fig. 3 is a bottom plan view of a machine embodying the invention.

Fig. 4 is a vertical section through the standard of the machine showing the connections from the drive shafttothe feed mechanism.

In the drawingsI have shown a sewing machine provided with the usual cloth plate 1 and the machine is also made with the usual vertical hollow column 2, leading from the base to the horizontal arm which contains the drive shaft 3 and has on its end the head 4 which carries the needle and the presser foot bar 6. A rotary shaft 7 is mounted below the cloth table carrying on its end any suitable rotary loop spreading means, as shown conventionally in Fig. 1, and being turned from the shaft 3 by suitable connections, such as the shaft 8 and bevel gear connections.

The feed member 9 is mounted just below the work plate and has teeth adapted to project up through that plate as usual, for the purpose of engaging the cloth. This feed member is pivoted at 10 to the end of an arm '11 which is rigidly secured to the rock shaft 12. The arm 11, as will be seen, extends upwardly and therefore any rocking movement of the shaft 12 will tend to the accompanying move the member 9 longitudinally so as to feed the cloth the extent to which the shaft rocks, controlling the amount ofthe feed or the length of the stitch. The member 9 is supported at its other end by a link connectionto an arm -13 secured to the rock shaft 14 and it will be observed that since i the arm 13 extends in a horizontal direction any rocking movement will raise and lower the end of the feed member 9, thus carrylng it up into engagement with the cloth and lowering it out of engagement. In the particular form shown the link connection between the arm 13 and member 9 consists of a brace rod or member 15 which has ball and socket connection with the two members and also includes the tension spring 16 which tends to hold the parts together. The rock shaft 14 is continuously and uniformly rocked while the machine is going to raise the feed member 9 into engagement with the cloth and to hold it there while it is being moved forward. A link arm 17 is pivotally connected to the end of the arm 18 carried by the shaft 14 and at its opposite end it is engaged by the eccentric 19 on the drive shaft 3. Each rotation of the drive shaft therefore raises and lowers the arm 18 and thus rocks the shaft 14 and raises and lowers the feed member 9.

The rock shaft 12 is operated to give the longitudinal movement to the feed member by the means shown in Figs. 2 and 4. That means includes an arm 20 secured to the shaft 12 and a link or rod 21 pivoted to the end of that arm. The operating link 21 has at its upper end two parallel arms 22, 23 and a slide block 24 fits between these two arms and is freely movable longitudinally of them. The shaft 3 has on it an eccentric 25 which fits in a central opening in the slide block 24 and therefore the rotation of the shaft 3 tends to oscillate laterally the upper end of the operating link 21. In order to give this oscillating action effect on the horizontal arm 20 carried by the shaft 12 I connect to the link 21 between its endsa link 26, that link being arranged at an angle to the link 21. This link 26 has a pivotal connection 27 to the link 21 and a pivotal connection 28 to one arm of the bell crank lever 29 whichhas a fixed pivot support 30 on the casing of the machine. The other longest stitch. In dotted lines the bell crank in its upper position where it a will be observed that the link 26 is almost,

arm of-the bell crank 29 extends out through a slot 31 in the wall of the upright column 2 and a thumb piece 32 is secured on it so as I to-serve asan operating handle and so as to permit tightening against the wall of the column to hold the bell crank 29 in any adjusted position along the slot 31. In Fig. 2 I have shown the bell crank in tion the feed member will be given its greatest longitudinal movement,

,I have shown parallel to the link 21 and when in this position the stitch formed will be the shortest.

By the constructionjust described it will be observed vthat the rotation of the shaft 5 is the bell crank, it is impossible for the upper end of the'link 21 to move laterally tends to oscillate the rod or link 21 laterally,

but since that link has the link connection 26 to a rigid support, which in this instance without at the same time moving longitudinally because the lower end of the link is connected to the arm 20 and cannot movegitudinal movement is necessary for the same lateral movement.

its lo.w est position in full llnes andwhen in'thils posi- 1 making the if the link 26 is in the posi Having thus described the invention what is claimed as new is:

In a sewing machine, the combination with a drive shaft, of stitchforming mechanism, a cloth plate, a clothfeeding member below said plate adapted to be raised through an opening thereinto engage the under surface of the. cloth, a rock shaft below said plate on one side, an upwardly extending arm on said shaft pivoted at its upper end to one end of said member to reciprocate it longitudinally-tr rock shaft on the opposite side of the machine'below said plate, anarm pperated by said second rock shaft extending in a substantially horizontal position, link connection between said horizontal arm and the free end of said feed member to raise and lowersaid member, a horizontal arm secured to said first mentionedrock shaft, an upwardly extending longitudinally movable link pivoted to said horizontal arm at its lower end and having separated parallel arms on its upper end, a slideblock mounted :on said parallel arms, an eccentric secured to said drive shaft and working in said slide block, a controlling link pivoted at its lower end to said longitudinally movable link between its ends, and a bell crank having one arm accessible from the outside of the machine and the other arm pivoted at 1 itsend to the upper end of said controlling link whereby the controlling link may be vmljusted to various positions vapproaching one parallel to the longitudinally movable link, In testimony whereof Iafiix my signature in presence of two witnesses.

j Witnesses: ARTHUR L. BRYANT, Lou Gene a;-

Gopi-es of this patent may be obtained for live cents each, by addressing the f Commissioner of latents,

Washington, D. 0. y

RICHARD KSHOHMANN. 

